CONTENTS OF VOL. XX. FIFTH SERIES. Vll 



Page 

 Prof. T. Carnelley on the Periodic Law, as illustrated by cer- 

 tain Physical Properties of Organic Compounds. — Part II. 

 The Melting- and Boiling-points of the Halogen and Alkyl 



Compounds of the Hydrocarbon Eadicals 497 



Drs. W. Ramsay and S. Toung on some Therm odynamical 



Eelations. — Part 1 515 



Mr. H. Wilde on the Velocity with which Air rushes into a 

 Vacuum, and on some Phenomena attending the Discharge of 

 Atmospheres of Higher into Atmospheres of Lower Density 531 

 Notices respecting New Books : — 



Prof. O. J. Lodge's Elementary Mechanics, including 



Hydrostatics and Pneumatics 545 



Mr. L. Clark's Transit Tables for 1886 547 



Visible Representation of the Eocus of Ultra-red Rays by Phos- 

 phorescence, by E. Lommel 547 



On the Tones produced in a Plate or a Column by frequent 

 Discharges of an Electrical Machine, by M. E. Semmola . . 548 



Index 549 



ERRATUM. 

 Page 163, line 4 from bottom, for -2478 read -2784. 



